Muffler



FIG. 1 is a top, front and left side perspective view of a mufflershowing my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a top perspective view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a right side elevational view thereof.

The ornamental design for a muffler, as shown.